A source in the investigating commission said, ''All the scheduled investigations will be completed within the next seven days.'' He said the chain of events would be reconstructed a day or two after the completion of the investigation, adding it had also been established that safety system of the submarine's nuclear reactor had been operating in automatic mode during the trials.

Earlier Capt 1st Rank Igor Dygalo, an aide to the Russian Navy Commander Vladimir Vysotsky, said the submarine's reactor had not been affected by the accident, which occurred in the nose of the vessel, and radiation levels were normal.

Meanwhile, Khabarovsk Governor Viktor Ishayev said the investigation revealed that the fire safety system had operated correctly and suggested that human error could have been a factor in the deaths.